Might I suggest having a look at this thread:
http://www.subsim.com/radioroom/showthread.php?t=164131
It's the SHV TDC tutorials thread - covers all types , manual and auto.
Many many thanks.
The auto TDC tutorial confirmed that even on auto you need to do some work...and I was doing it all wrong.
Very different to SH3, but change is good sometimes. I shall give it a whirl again tonight...I have the game saved right before I make my final run to position the sub...just like in the vid.
